The present invention relates in general to fluid handling systems and multi-positionable valving arrangements for use therein; and, more particularly, to fluid handling and valving systems of the type used to supply fluid from a selectible one or ones of n (where n is any whole integer greater than "1") fluid source means--e.g., n fuel tanks--to all or a selected one or ones of m (where m is any whole integer greater than "1") fluid utilization means--e.g., m diesel engines or the like--and, for returning the excess or unused fluid supplied to the m utilization means to a selected one or ones of the n fluid source means. When the present invention is used to supply fuel from one of n fuel tanks to all or selected ones of m engines, the excess unused, or unburned, fuel supplied is commonly returned to the particular one of the n tanks from which it was supplied; but, in its broader aspects, the invention permits of return of excess unused fluid to a different selected tank or tanks in those instances where desirable.
While those skilled in the art will appreciate as the ensuing description proceeds that the present invention will find use in a wide range of fluid handling systems wherein there is a requirement to deliver fluid from a selected one or ones of a plurality of sources to all or a selected one or ones of a plurality of discrete utilization points, and to return excess or unused fluid from the plurality of discrete utilization points to a specific one or ones of the sources, the invention finds particularly advantageous use in those areas where a plurality of diesel fuel powered engines are utilized to provide motive power for, for example, marine vessels such as ships having multiple engines, large fishing or pleasure boats, tractor-trailer rigs hauling freight over highways, farm implements, passenger cars, and numerous industrial and/or process control applications.
Thus, it will be appreciated that the typical two-stroke diesel engine is an internal combustion power unit in which the heat of fuel is converted into work in the cylinder of the engine. In the diesel engine, air alone is compressed in the cylinder and, after the air has been compressed, a charge of diesel fuel is sprayed into the cylinder and ignition is accomplished by the heat of compression. Shortly before the piston reaches its highest position with the cylinder, the required amount of diesel fuel is sprayed into the combustion chamber by a fuel injector. The intense heat generated during compression of the air ignites the atomized fuel immediately. Because of the intense heat at or near the fuel injector, diesel engines may use portions of the diesel fuel itself to cool the fuel injector since, as fuel temperature increases, the performance of the engine is adversely affected. Surplus fuel which is used as a cooling agent is then returned to the fuel tank for subsequent use either as a cooling agent or as the source of motive power. Therefore, fuel lines and valving arrangements must be provided which serve not only to direct diesel fuel from the fuel tanks to the engines but, also, which serve to return unused fuel from the engines to the fuel tanks.
In many applications such, for example, as commercial fishing vessels or large pleasure boats, multiple fuel tanks may be utilized in conjunction with two or more engines. Such engines may function either as a source of motive power for the vessel or, alternatively, they may comprise one or more auxilliary engines which are utilized for purposes other than providing motive power for the vessel itself. Typically, all motive power engines and, perhaps one or more of the auxilliary engines as well, will be operating simultaneously and will be fed from the same fuel tank. As a particular fuel tank approaches or becomes empty, fuel must be directed to the engines from a second fuel tank. This process may be repeated a number of times depending upon the number of fuel tanks to be utilized.
So far as applicants are aware, conventional prior art fuel delivery systems require individual valves for controlling the fuel being delivered to each engine and the fuel returning from each engine. That is, in a system employing two tanks and two engines, four valves would normally be required--viz., a first valve for delivering fuel from tank No. 1 to both engines; a second valve for delivering fuel from tank No. 2 to both engines; and, third and fourth valves for returning unburned fuel to tank Nos. 1 and 2, respectively. The number of valves required is, of course, magnified where more than two tanks and/or engines are used. Because the valves associated with each fuel supply and fuel return line for each tank are typically arranged in close proximity to one another in order to reduce the time required to close one tank and open another tank, it is not an uncommon occurrence for one to activate the incorrect valves and, therefore, disrupt the flow of fuel to the engines. Alternatively, one may inadvertently close the valves associated with the nearly empty tank before opening the valves associated with the new tank. In either case, if the fuel lines to the engines are run dry, air will enter the lines and the engines will have to be primed in order to be restarted--a difficult and cumbersome process.
Other problems associated with multiple fuel tanks in a marine situation or with other moveable vehicles having multiple fuel tanks, involve the waste, potential environmental damage, and hazards resulting from spillage of fuel. For example, fishing vessels typically have at least two fuel tanks--one on either side of the hull--with a balancing line connecting the lower portions of the fuel tanks and which serves to maintain approximately equal fuel levels in each tank for purposes of balance. The tanks are also provided with an overflow port on an upper portion of the tank. Therefore, if a vessel having dual fuel tanks which are substantially full lists to one side for whatever reason (such as wind blowing broadside to the vessel), fuel will flow from the upper windward tank to the lower fuel tank through the balancing line; and, since the lower fuel tank is already full, fuel will be spilled through the overload port into the water. By the same token, a diesel powered truck having full fuel tanks and resting sidewise on a slope would experience the same problem. In either case, not only is there a substantial hazard due to the spilled fuel, but the environmental damage and economic waste is obvious.
In addition to the problems associated with known prior art designs, a typical vessel with two engines and four fuel tanks would have at least eight valves and more than thirty fittings. The costs of providing this large number of valves and fittings in a competitive situation are enormous.
The most pertinent prior art of which applicants are presently aware is that disclosed in Studdard U.S. Pat. No. 1,282,650 wherein the patentee discloses a valve permitting unidirectional movement between two object points. More specifically, the patentee discloses an elongated tapering rotary valve within a casing which may be moved between one of three positions. The rotary valve is provided with apertures or ports for communication with lines affixed to the casing. In a first position, all of the ports in the valve are closed except a single port which permits the flow of gasoline from a gasoline tank to an internal combustion engine. By rotating the valve member, the flow of gasoline is stopped and kerosene and water are permitted to flow through the valve to the engine, while exhaust gases will pass through the casing and valve to a muffler. In its third position, the valve closes all ports except one which permits the withdrawal of kerosene from the engine carburetor and its return to the kerosene tank.
Other prior art which has come to the attention of applicants includes the following: Ross et al U.S. Pat. No. 796,252 which discloses a conventional mixing faucet wherein two different liquids are mixed and discharged from a common outlet; Meldau U.S. Pat. No. 876,724 which discloses a stop-cock valve for permitting introduction of compressed air into beer kegs; Strother U.S. Pat. No. 1,501,146 which discloses a valve of the type used with an air brake for automobiles; Turak U.S. Pat. Nos. 2,733,730 and 2,733,731 which disclose a flow-controlled unidirectional dispensing valve used to mix soft drink syrups with carbonated water; Johnson U.S. Pat. No. 2,908,293 which discloses a unidirectional valve in which fluid is supplied through a single inlet and discharged through a selected one or ones of three discharge outlets and/or a bypass outlet; Sanders U.S. Pat. No. 3,319,531 which discloses an integrating valve for delivering hydraulic fluid under pressure to a plurality of cylinders in selected exact quantities; Baity U.S. Pat. No. 3,590,872 which discloses a disk-type unidirectional valve in which fluid from a single source may be delivered to a single point or to one of two points; and, Okadi U.S. Pat. No. 3,734,409 which discloses a mixing valve for mixing cold water and steam in a mixing chamber at given rates and delivering the hot water produced through a single outlet.
Because of the significant costs involved in providing the numbers of valves necessary in fuel supply systems heretofore in use, and because of the safety and environmental hazards incident to their use, there is, and has been, a continuing urgent requirement that a fluid supply system--especially, a fuel supply system--be provided which eliminates not only a large number of valves and fittings, but, which also reduces the chance of spillage of fuel or other fluids and/or the need to prime engines which have had their fuel supply cut off due to an inadvertent mistake by the operator.